From chameleons to octopuses, many creatures throughout the animal kingdom change their skin colour for camouflage, temperature control or communication.

Now, scientists have taken inspiration from such creatures, replicating their colour-changing abilities with artificial electronic skin.

Their incredible material could be used in a variety of ways in the future, including in robotics, prosthetics and wearable technology used by armed forces.

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Researchers from Tsinghua University in Beijing have now developed a new type of electronic skin, with a colour change easily seen at just 0-10 per cent strain

HOW DOES IT WORK?

The material is made from graphene - a form of pure carbon that is 200 times stronger than steel.

Two layers of graphene are included - a highly-resistive strain sensor, alongside a stretchable organic electrochromic device (ECD) that changes colour when a current is applied.

While other colour-changing materials require enormous strain of 100-500 per cent to change colour, the researchers found that subtle strain - between zero and 10 per cent - was enough to cause an obvious colour change.

Previous studies have created colour-changing artificial skin, but the colour changes have only been visible to the naked eye when the material is put under enormous strain of 100-500 per cent.

But researchers from Tsinghua University in Beijing have now developed a new type of electronic skin, with a colour change easily seen at just 0-10 per cent strain.

The material is made from graphene - a form of pure carbon that is 200 times stronger than steel.

Two layers of graphene are included - a highly-resistive strain sensor, alongside a stretchable organic electrochromic device (ECD) that changes colour when a current is applied.

Dr Tingting Yang, who led the study, said: 'We explored the underlying effect on the electromechanical behaviour of graphene.

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'To obtain good performance with a simple process and reduced cost, we designed a modulus-gradient structure to use graphene as both the highly sensitive strain-sensing element and the insensitive stretchable electrode of the ECD layer.

'We found subtle strain - between zero and 10 per cent - was enough to cause an obvious colour change, and the RGB [red green blue] value of the colour quantified the magnitude of the applied strain.'

The material is made from two layers of graphene - a highly-resistive strain sensor (labelled Stiff PDMS), alongside a stretchable organic electrochromic device (ECD) that changes colour when a current is applied

'However, our results also show that the mechanical property was strongly relevant to the performance of the strain sensing materials.

'This is something that has previously been somewhat overlooked, but that we believe should be closely considered in future studies of the electromechanical behaviour of certain functional materials.'

During testing, the researchers found that subtle strain - between zero and 10 per cent - was enough to cause an obvious colour change, and the RGB [red green blue] value of the colour quantified the magnitude of the applied strain

While the material is still in its early development and is not yet ready to be implemented into devices, the researchers believe it has the potential to be used in a range of sectors.

Dr Yang added: 'It's important to note that the capability we found for interactive colour changes with such a small strain range has been rarely reported before.

'This user-interactive e-skin should be promising for applications in wearable devices, robots and prosthetics in the future.'

While the material is still in its early development and is not yet ready to be implemented into devices, the researchers believe it has the potential to be used in a range of sectors, including robotics, wearable devices and prosthetics in the future